Logic Puzzle
Tests an AI's ability to solve a simple but potentially confusing logic puzzle
The Prompt
Sally (a girl) has 3 brothers. Each brother has 2 sisters. How many sisters does Sally have?
Model Responses
Sally has only one sister.
Explanation:
- Sally has 3 brothers.
- Each brother has 2 sisters.
- The two sisters are Sally and one other girl.
Thus, Sally has 1 sister.
Let me help solve this word problem step by step.
Let's break it down:
- Sally is a girl
- Sally has 3 brothers
- Each brother has 2 sisters
The key insight here is that if each brother has 2 sisters, and we know Sally is one of those sisters, then all brothers must share the same sisters.
Since each brother has 2 sisters total, and we know Sally is one of them, there must be one other sister.
Therefore, Sally has 1 sister.
To verify:
- Sally + her 1 sister = 2 sisters total
- This matches the fact that each of the 3 brothers has 2 sisters
The answer is 1 sister.
This is an interesting logical reasoning problem! Let's work through it step by step.
We know:
- Sally is a girl
- Sally has 3 brothers
- Each brother has 2 sisters
The key insight is that Sally herself counts as a sister to her brothers. So when we're told that "each brother has 2 sisters," Sally is one of those sisters.
Since each brother has 2 sisters total, and Sally is one of them, that means each brother has 1 sister besides Sally.
But all brothers share the same sisters (they're all siblings in the same family). So if Sally has 3 brothers, and each brother has the same 2 sisters (Sally and someone else), then Sally has exactly 1 sister.
Therefore, Sally has 1 sister.
To solve this problem, I need to analyze the relationships carefully.
Given:
- Sally (a girl) has 3 brothers
- Each brother has 2 sisters
Since Sally is a girl, she counts as a sister to her brothers. So each of Sally's brothers has Sally as one of their sisters.
If each brother has 2 sisters total, and one of those sisters is Sally, then there must be exactly 1 other sister that all the brothers share.
Therefore, Sally has 1 sister.
Sally has 3 brothers. Each brother has 2 sisters. Since Sally is one sister, there must be one more sister to make the total number of sisters each brother has equal to 2. Therefore, Sally has 1 sister.
Answer: Sally has 1 sister.
Sally has one sister. All of Sally's brothers share the same two sisters: Sally and one other girl.
Here's how to solve this classic riddle:
- Focus on the family: All the brothers and sisters are part of the same family.
- Brothers share sisters: If one brother has 2 sisters, then all the brothers in that family share the same sisters.
Since each brother has 2 sisters, and Sally is a sister in the family, those 2 sisters must include Sally and one other sister.
Therefore, Sally has 2 sisters.
First, note that each of Sally’s three brothers has exactly two sisters. One of those sisters is clearly Sally. Since each brother’s two sisters must be the same two girls for all of them, there must be exactly one other sister besides Sally.
Therefore, Sally has 1 sister.
Sally has 1 sister.
Explanation:
Sally's 3 brothers each have 2 sisters. Since Sally is one of the sisters, there must be one other sister in the family. Thus, aside from Sally, there is one more sister.